Resilient fair-lead



NOV- 14, 1950 w. s. cLARKsoN ETAL 2,529,485V

RESILIENT FAIR-LEAD Filed March 9, 1945 I. 2 Sheets-Sheet l 3mm/tofu w. s. CLARKSON J. H. RUPE Nov. 14, 1950 w. s. cLARKsoN E-rAL 2,529,486

RESILIENT yFR-LED Filed March 9, 1945 2 Sheets-Sheet 2 3 mit-v @Mmmm 4. W

' Patented Nov. 14, 1950 RESILIENT' FAIR-LEAD William S. Clarkson, Washington, D. C., and Jack H. Rupe, Mount Rainier, Md.

Application March 9, 1943, Serial No. 478,510 9 Claims. (c1. 25er- 190) (Granted under the act of March 3, 1883, as amended April 30,1928; 370 O. G. 757) l This invention relates to an improved fairlead for the anchor of a buoyant marine mine. More specifically, the invention relates to a fairlead of new andimproved construction secured to the casing of a mine anchor adapted to pay out a length of ,cable therefrom through the fairlead until the mine has reached a predetermined depth of submersion within the water whereupon further paying out of the cable from the anchor is arrested.

In mine mooring devices heretofore devised in which a buoyant mine is releasably secured thereto before the mine' is launched, itis the general practice to pay out the mooring cable through an annular shaped fairleadv composed of metal or lignum vitae, as the case maybe, secured to the casing of the mine anchor, the mooring cable being payed out from a drum arranged within the anchor casing. W'hen the mine has risen to a predetermined depth ofv vsubmersion within the Water the drum is locked thereby preventing additional paying out of the cable from the mine anchor thereby mooring the mine at a predetermined depth of submersion within the'body of Water by the mooring cable and mine anchor. Considerable difliculty has been experienced heretofore vwith this type ofy mine as the result of Wear of the fairlead caused by the movement of the mine within the Water in response to tidal currents, storms and the like thereby causing the mooring -cable to be flexed sharply against the fairlead, this flexure being accompanied by a rubbing motion between the cable and the fairlead sufficient to wear through the fairlead within a relatively short period of time, the rate of wear being, in some cases, accelerated by the presence of sand or other abrasive material introduced between the cable andthe fairlead by movements of the water within which the mine is planted. lWhen theV mooring cable wears through the fairlead, it comes into contact with the casing of the mine anchor or the fairlead support and it has been Vfound that the frictional movement of the mooring cable against the e'xposed metallic surface of the mine anchor or the support causes the cable to be worn rapidly and weakened sufficiently to sever the cable and release the mine `from the anchor Within a relatively short period of time.

This difficulty s overcome by employing a fair- Y' Y :moment applied to the core by the cablecauses lead in accordance with the present invention in which the fairlead is composed of an inner sleeve portion or core through which theV mooring cable is adapted to slide arranged within `a resilient cylindrical bushing secured to the casing of the mine anchor by a'A cup shaped support within which the bushing is arranged. The core is composed of a flexible material such, for example, as

Vin'g a degree of hardness suilicient to impart a relatively greater flexibility thereto than the flexibility 'of the core. 1

An arrangement is thus provided in which the radius of curvature of the cable at the point of 'emergence thereof from the mine anchor is greatlyY increased by reason of the relatively high flexion resistance of a'sleeve withinr which the cable is arranged and which extends alongthe cable for a distance suliicient to apply pressure thereto 4substantially uniformly whereby the bending force is Ydistributed along that portion of the cable in contact with thev core and the `instant pressure applied to the cable at any one point along the radi-us of curvature is greatly reduced. By

`supporting the core Within a resilient bushing of greater flexibility than the core, the Ybending the core tol assume a radius of curvature corresponding substantially to the radius of curvature of -that portion of the mooring cable in contact withfthe fairlead by reason of the resilience of the bushing Within which the core is supported in a manner such that the shock of impact kof the cable against the fairlead as the result of movements of the mine within the water and/ or vibrations of the mooring cable is reduced. Thelower end of the core is provided with an enlarged end section or head Aformed integrally ytherewith adapted to permit a small endwise movement of the core by engagement with the lower end of the l resilient bushing or the lower inner portion of the cup shaped support, as the case may be. The upper end of the core is reinforced in any suitable manner as by a ring or sleeve of suitable material such, for example, as metal arranged thereabout thereby to prevent damage to the -upper end of the sleeve in contact with the cable as the result of pressure applied thereto by the cable.

One of the objects of the present invention is to provide a new and improved fairlead for a mine for yieldably guiding and protecting the mooring cable thereof at or near the point of emergence of the cable from the anchor casing.

Another of the objects is to provide a new and improved fairlead having a relatively hard wear resistingsurface in engagement -With the mooring cable in which the bending characteristics ol a relatively flexible fairlead are retained.

Another object is the provision of a new and improved fairlead for a marine mine in which the ,n rate of wear of the fairlead and the mooring cablearranged therein is greatly reduced. I'

Another object is to provide a new and improved fairlead having means for reducing the shock of impact of the cable thereagainst.

Another object is to provide a new and improved fairlead having means for reducing the shock thereagainst caused by vibration of the cable of a moored mine.

-Another object is to provide a new and im- -inve'dv fairl'e'ad forfav nflarir'i'e mine linwhich lthe rateof'fatigue of the-mooring cable at the point of eineragencehfromj-th-e mine anchor as the result offmovem'e'nts -of-the mine lwithin the water is greatly reduced. Y

Another object is Vto provide a new and irnp'rove'dresilient fairlead havingmeans-for substantiallyinvcreasing the radius of curvature of a predetermined length of the mooring cable in response tormovement of the'rnoored-mine about "i aipredeterlr'nined initial position. Y Y- f'fAnother object is theprovision of affairlea'd adapted tor apply substantially uniform bending mo'r'ien't toy a Vpred'e'termined length of mooring 'cablefof a lmarine''mine vasthemine moves about r'nin'efanchors'n-owfin general use which is eco-4 'noinidalftomanufacture; 'reliable in operation and whichpossesses allvof the vqualities of ruggedness StilL-other objects, advantages andimproveand' -durability' in service.

"merits'will be apparenti-rom the followingl description 'taken in-con'nection with' the l:accontpanyingdrawings-cf-whieh;

-"l=ig- -l 'is a View in elevation'ofra moored-mine employing the' 'fairleadi ofthe present invention; vF'i'glfiZ is a greatly enlarged plan view partly vbrokenaway`'of the upperportion vof the mine anchor casin'g showing"- the-"fairlea'dsecured 'tli'f'r'eto' 'i *friggere a yiewpparuy broken away and partly in -section"taken'along'the line 31-3 of Fig'. 2; f Figgl "is 'ayiewsimilarto Fig. 3 in which the mooring cable and fai'rleadV are Shown flexed'as thei"esult of movement of the'mine from'the position' shown in Fig. 1;'r

' Fig. 5 is ayieWinperspeCtive showing a pre- .ferrdfo'rm of ar'esilient supporting sleeve Jemplbyedwith the presentfinvention; and,

Fig'is'a "view in perspective of a preferred form of resilient "core suitable for usev with the sleeve of VF'ig.5. Referring now to the drawings fora better understanding of ythe invention on rwhich like numerals of reference are employedto designate like parts throughout the several views and more particularly to'Fig'. 'l thereof, there-.is shown thereon a mine anchor indicated generall57 by the numeral II having a recessed portion or chamber I2 therein within which is rotatably mounted as at I3 a drum or reel I4 having a mooring cable I5 secured thereto. lThe mooring cable is wrapped about the drum and passed over the cable guide IE secured to the casing of the anchor in any suitable manner and having an arcuate surface thereon adapted to guide the cable as it leaves the drum, the cable thereafter passing throughY aY fairlead indicated generally by the numeral I'I, The other end of the lcable is secured to the eye bolt I8 secured to the casing of the mine i9. The mine may be ofv any suitable type adapted to rise within the water by reason of a positive degree of buoyancy imparted I5 through the fairlead after the mine has been launched within the body of water and disengaged from the mine anchor.

The mine, it will be noted, is supported prior to the launching thereof by the supports 2l atand maintained securely thereagainst by reason of the provision of certain link members which engage the hooks 22 and 23'secured tothe casing of the mine. -Therelease arm 24 is pivotally-secured Ytothewmine casing at 25 and releasably maintained in the position shown in solid outline on-Fig. 1 by reason of1certain control mechanism arranged withinv thecasingZB adapted to unlock the' arm* 24 and-release the mine from locked engagement with the anch-or as the mine is launched,v the armf'24 moving to the position Shown in dashed outline as the mine is released, asis well known in the art to which the present invention pertains.

f The mine'is also provided'with a cover or cap '2l secured thereto a's by the bolts 28 whereby the vmine is adapted to be hermetically sealed after an explosive chargeland firing mechanism have been: assembled therein. Preferably, though not necessarily,the. casing ofthe mine anchor -is provided with a' valve comprising a spring actuated' 'plunger 29 adapted to be released as the mine moves away yfrom the casing thereby to admit Water within the casing of the mine anchor and 'decrease the buoyancy` thereof, as is well known'in the'art. The mine anchor is provided witha'rdow'nwardly extending portion 3l to which Iis secured the wheels.'32 whereby the launching of'fthe mine isfacilitated. The portion 3l of the mine anchor is'also adapted' to enclose and support a heavy weightoraA plurality of Weights whereby' the mine anchor'isV maintained in fixed engagement with the bed of the body ofwater regardless of the action of tidal currents or other movementsof Ithe water tending 'to cause the mine anchor to be shifted'from the initial planted position thereof. i "f Therfotatable' drum may-be 'of any type suitablefor"'the 'purposesuchy -forxexample, as the differential drum for mine anchors disclo'sedlin the copending applicationof James B.: Glennon, Serial No. 635,117, iiled September 27,1932, for Diierential Drum for'Mine'Anchors, now Patent No. 2,435,580, dated February 10,'1948, in which the :cable is payed out from a cable drum until the mine is moored ata predetermined-depth within the water, and in which means are provided for locking'thedrum to the mine anchor when the predetermined depth of submersion of the minewithin thewater'yis reached. The casing of the mine anchor ycomprises a plate 33 securedxt-hereto as bythe-bolts -34yhaving an aperture 35 therein adapted to receive the upper portion of the fairlead vI1 comprising the resilient sleeve or bushing member' 36 1 and flexible core 31. y l V The sleeve 36 is preferably annularin shape and composed of resilient material suitable for the purpose such, forexample, as rubber or any of thersynthetic varieties thereof, the outer surf-ace of the sleeve being cylindrical and adapted to t slidably within the cup shaped support 38 secured to the plate 33vas by the'bolts 39,-nuts 4I and washers 42. The Vexternal diameter of the upperV portion of the sleeve 36 is reduced at 43 sufficiently to permit a lateralmovement of the upper portionof the sleeve within the laperture 35 as the cable I5 is flexed. Substantial movement of the sleeve member 36 upwardly is prevented by engagement of the shoulder 44 formed thereon with the inner surface of the plate 33. The sleeve is also provided with a portion 45of lreduced external diameteradapted to permit a certain amount of lateral movement of the lower end of the core 31 as thel cable I5is flexed. The sleeve 36 is also provided with; a cylindrical aperture 46 within which'theY core 31 is arranged,

the end of the core having van outwardly projecting collar 41 formed preferably integrally therewith adapted to engage the lower, portion of the sleeve member 36 and the bottom of the cup shaped support ,38, the diameterr of thev shoulder 41 being somewhat less than the inner diameter ofthe cupshaped member and somewhat greater'than the aperture `48 formed within the bottom of the cup 'shaped member.

,The upper portion of the core 31 is provided Y with a sleeveor ring 49 preferably having an inwardly projecting portion f liln'adapted to engage the core and maintainthefring securely fixed thereto at all times thereby reinforcing and sup'- porting the upper end ofthe core sufciently to l prevent damage theretornas the mooring cable is flexed. The core isalso provided with an aperture 52 arranged axially therein within which the cable I5 is adapted to slide, the sliding movement ofthe cable being facilitated by reason of the provision of chamfered or tapered portions 53 and 54 in abuttingv and aligned relation with respect to the apertured portion 52. l,

The core 31 is composed preferably of rubber or any of the synthetic Yvarieties, thereof ofsuiii-v cient hardness to present a Vtou'gh'wear resisting surface to the cable I5" at the apertured portion 52 thereof and possessing lsufficient"flexibilityto Aenable the core `to be flexed arcuatelyin response to movementsv of the minel within the water. The sleeve member 36wisal'so composed/ of flexible resilient material such, xfor example, as rubber or any of the synthetic,varietiesjthereof having a greater degree of flexibilityand compressibility than the core 31 wherebythe sleeveis adapted; to be. deformed by compression4 of a portion' thereof as the cable I5 is flexedl from the initial vertical position thereof within 'the `water. .l

This will best be understo'odbyreference to port 3B respectively'. f Y 'Y y Under certain conditions of Vservice it has been jffound that' a moored mine may perform a ro- Fig. 4 on which is shown the core 31 flexed toM the right'by the mooringcable I5, the axis of the` core substantially coinciding with the axis of the cable throughout that portion of the cable included within the core. The core 31 and cable are thus exed along the arc of a circle of relatively large radius by reason of the pressure 'l applied to the core by the resilient sleeve. mem- I ber'36 which, as will bevnoted, is forced into engagem'ent .Withtheapertured portion 35 of Atheplate 33 and the inner cylindrical portion of the cup 'shaped "support 38 "respectivelyi "The 'lower ment of the portion of the sleevemember 36 is also vcompressed outwardly and upwardly by the lower portion of the core 31'comprising the collar l41 formed thereon.

The lower end of the core 31 including the collar 41 is thus tilted at an angle such that the collar 41 on the opposite side thereof is forced lagainst the bottom of the cup shaped support 38. From the foregoing it will be apparent that there is provided a tough wear resisting core having a low degree of exibility in contact withr the mooring cable throughout a considerable length of cable in which the core' is yieldably supported by a resilient sleeve having a higher degree of flexibility and compressibility than the core-disposed within a'rigid cup shaped member. VThe core is thus adapted to ex uniformly along the arc of a circle of relatively large diameter as the cable is flexed by reason of the uniform distribution of pressure applied to the'core by the resilient sleeve as the sleeve is vcompressed by the horizontal component of the force applied to the cable I5 by the mine as the mine is moved laterally from yan initial rest position directly above the fairlead. Y Q Y By providing` a core in which Athe koutwardly extending portion thereof is enclosed within, and reinforced by an annular protecting member ,adapted to follow the movements of the core as the cable is flexed, the upper end of the core in `contactwith the cableis given additional support by the aforesaid annularmember sufcient to prevent the Vcore fromA becomingv damaged or torn by the pressure of the cable against the upper portion thereof. Furthermore, by provid- Ying afairlead comprising a core composed of wear resisting material combined witha low degree of flexibilityarranged within va cylindrical support having a higher degree of flexibility and compressibility than-the core, the wear resulting from the flexion and tension of the mooring cable as ythe mine moves within the water about additionally reducedby reason lof the engagecollar 41'v` with the lowerportion of the'resilient sleeve 3I`andV the cup shaped suptary movement or path of travel through the water in response tojaflow of water past the mine such, for example, as may be caused by tidal currents and apply a sudden tug or jerk of increased f tension4 to the mooring cable concurrently 'with each such rotary movement or 'path of travel of the mine and, furthermore, the relative movement of the cable with respect tothe water may ca use a vibrating condition to be set up in that portionf of the mooring cable intermediate the mine and the and thereof is substantially freducedy with a correanchor. By employing a resilient fairlead in accordance with the present invention, the fairlead responds lyi'eldably to each such vibration or tug of the cable and thus the degree of Ivibratory or oscillatory movement of the cable 't the frequency and' rhythm 'of movement spending. reduction inthe lwear of; the fairlead and the rate of fatigue ofthe mooring cable.

j AWhile the invention has been described-with particularity as to one preferred embodiment and a combination of mechanismsY and of each of the various elements of the combination, it -is to be understood that this has been done for purposes of disclosure and that various changesv and substitutions may be readily-apparent to those skilled in l-the art, after understanding the invention herein disclosed, and that'rthe terms employed in the claims are, therefore, to be considered as Words of description rather than of limitation.

j The invention herein describedand claimed may be manufactured and used by or for the Government of the-United States of America for governmental purposes without payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

-1., In a fairleadformounting on a plate having an aperture therein, a central core having a bore therethrough, a sleeve having a central ybore Atherethrough within whichthe core is tightly tted, said sleeve having a reduced upper section fitting-loosely in the aperture in the plate and an enlarged central section, a cup having a central aperture and adapted totightly grip said enlarged v central section of thesleeve, and means for attaching the cup to the plate with saidl central aperture thereof inalinement with said core.

" 2. In a fairlead for mounting on a plate having an aperture therein,'a central core having abore therethrough and a collar on the bottom portion thereof, a sleeve having a central bore therethroughwithinwhich the core is tightly fitted,

said sleeve having a reduced' upper section fitting vloosely in the aperture inv the plate, an`enlarged lltralsection, anduaureduced'lower section engaging said collar, a cup .having'a central aperture and adapted to tightly grip said enlarged central section ofthe sleeve, an'dmeans forattachingv the cup to the 'plate' with said central aperture thereof in alinement with said core.

` 3. Ina fairlead for mounting on a plate having an aperture therein, a central core having a bore therethrough, a sleeve having a central bore therethrough in' which the core is tightly tted, said sleeve having a reduced upper section fitting loosely in the Vaperturev the plate,:anenlarged central sectionand za' reduced lower section, a cupv having` a"c'entralfaperture v in `the bottom thereof andtightly gripping-the enlarged central section of' the sleeve; means for attaching the cup to the plate Ywith`the central aperture thereof in alinement with saidcorefand a collar onthebottointof the central core andengaging the lower'reduced-section 'of the sleeve, said -colvlar being' of greater diameter than the central aperture' in the cup andspaced a predetermined distance from the bottom of the cup.

4;*In'a fairlead for a Ymine anchor adapted to pay outa length of rmooring,cabletherethrough 'vas-,the mineis planted, va central'core having a lbore thereinV through Whichfthe vcable-is payed out, said core being composed of resilient masterial of sucient stiffness to provide a large -radiusof curvature of the portion of the cable in contact therewith as the mine weaves within the water, and a bushing disposed about said core and constructed and 'arranged to support the core and?` apply a1 lateral force thereto Vas the cable r isbent bythe pull of the-mine thereon, said bushing being composed of material of greater resilience' than the corel whereby no appreciable rear ofthecoreis effected v as the cable is bent bythe pull ofthe mine.

5. In a fairlead for a mine anchor adapted to pay out a length of mooring cable therethrough as the mine is planted, a cylindrical fiexible core having a bore therein through which the cable is payed out, said core being composed of Wear resisting material of suflcient stiffness to provide a large radius of curvature of the mooring cable disposed therein as the mine is pulledlaterally by a moving current within vthe water, a cylindrical bushing arranged about the core and composed of material having vgreater resiliency and compressibility `than the core for yieldably supporting the core and preventing wear at the outer surface thereof whereby the cross section and stiffness of the core is not reduced as the result 0fthe movements of the mine within the water, andmeans including an annular support arranged about said bushing for securing the bushing to the anchor, said vlast named means having an aperture therein of greater size than the diameter of the cable within which the cable is arranged. 6. In a fairlead for a mine anchor adapted to pay out a length of mooringcable therethrough as the mine is planted, a flexible core having a bore through which thecable is payed out, said core being composedrof resilient wear resisting material of sui'licient stiffness to provide a large radius of curvature of the cable therein as a lateral force is applied thereto by the mine in response to a moving currentfwithin the water, an annular resilient bushing having an axial length less than said core and composed of material of greater compressibilityand lessfwear resistance than the core yWithin Whichthe core is'arranged, and means including a cylindrical support forsecuring said-bushing tothe mine anchor. Y

y '1. In a fairlead for a mine anchor adapted to pay out a lengthY of mooring cable therethrough as the mine is planted,'aflexib1e core having a bore therein through whichV the cable is payed out, said core being,V composed of resilient wear resisting material of sulcient stiffness to provide a large radius of curvature of the cable therein as a lateral force is applied thereto by the mine in response to a moving current within the water, an annularV resilient bushing having anaxial length less than said core and composed of material of greater compressibilityand less V.wear resistance than thecore within which the vcore is arranged, meansY including a cylindrical vsupport for securingsaidbushing to the mine vlength of mooring cable slideably arranged therein,-.said fairlead comprising a pliable core of .wear resisting material and having-a bore therein` eX- tending along a considerable .length of thecable and 0f sufficient size to permit axial movement of the cable with respect thereto, .and means including a resilient support composed of material of greater resiliency and eXibility-than-the core arranged intermediate the core and anchorfor reducing the forceY of impact of thecable against the core as the mine mvessuddenly within the water.

.9. In a fairlead for -a mine anchor having a mooring cable therein, a. pliable core composed of tough wear and bend resistingv material, said core extending alongth'e'cable for a length suflicient toprovideav large radius of curvature therev 2,529,486 9 10 of as the mine is moved laterally within the water REFERENCES CITED in response to a moving current and having a The fono in r f r n bore Within which the cable is payed out as the fue of thsgatnt e e ces are of record m the mine is planted, and means including a resilient annular member arranged about said core and 5 UNITED STATES PATENTS composed of material having a resilience greater Number Name Date than the core and of less length than the core 887,877 Trumbull May 19, 1908 whereby pressure is applied to the Core by the 1,072,928 Elia Sept. 9, 1913 member exterially and variably in accordance 1,314,660 Huber et al. Sept. 2, 1919 with the tension and exion of the cable there- 10 1,321,775 Schneider Nov. 11, 1919 against. 2,190,880 Moss Feb. 20, 1940 WILLIAM S. CLARKSON. 2,249,609 Jackson July 15, 1941 JACK H. RUPE. 2,311,427 Winkelmeyer Feb. 16, 1943 

